This invention relates to cases for spectacles and, more particularly, to inserts for such cases which serve as protective sheets surrounding the spectacles.
The need for protective devices for conventional eyeglasses and sunglasses is evident. The lenses and frame of the average pair of spectacles are very fragile and easily damaged by abrasion and external pressure. Yet such eyeglasses may, and often must, be carried by their owners under the varied circumstances of daily life, and be readily available for use at any time. When not required, or in the way, they may have to be removed and quickly put away in order to free their wearer's hands. The pocket or pocketbook, while convenient, proves to be a generally poor, and all too frequently a downright dangerous, repository.
Many protective devices have been proposed in the prior art in recognition of the need to combine convenience of use and protection from mechanical damage and abrasion in an article which can be produced en mass for sale at a reasonable price to the user.
Rigid spectacle cases of metal and plastic materials and provided with a variety of hinged lids are known and widely used. They are inconvenient to use, generally requiring two hands for the removal and insertion of a pair of spectacles, expensive to construct, and easily damaged.
The most commonly encountered spectacle case of the recent prior art, the slip-in soft-walled sheath, is simple to use and economical to manufacture, but provides poor protection against damage.
Attempts have been made, notably in U.S. Pat. No. 2,758,707 issued to Baratelli in 1954, to provide slip-in spectacle cases with a metallic stiffener. Due to their relative high manufacturing cost, such cases have not attained any significant public acceptance.
It is, therefore, the primary object of the subject invention to teach the construction and use of an easily, massproduced, inexpensive, durable stiffening sheath which is readily insertable into a slip-in spectacle case to provide protection for its contents against mechanical damage and abrasion.
The subject invention provides for a protective liner, or stiffener for slip-in spectacle cases, comprising a thin resilient metal sheath with a soft facing cemented thereto. The metal sheath is a generally U-shaped structure, symmetrical about a plane passing through the base of the U, whose cross-section corresponds substantially to the cross-section of a slip-in spectacle case of conventional construction.
The stiffener is formed with its legs spaced some distance apart so that they must be forced together for insertion into the spectacle case. The natural resilience of the structure insures frictional engagement of the external surface of the stiffener with the internal surface of the case and prevents the stiffener from accidentally slipping out of the case. It is withdrawn by forcing the legs together to release their frictional grip on the inner wall of the case.
The stiffener may be constructed of any of a variety of convenient resilient sheet materials. However, consideration of strength, weight, resilience, workability, resistance to corrosion, cost and other factors suggests alloys of aluminum as prefered materials. Undoubtedly non-metallic, e.g., plastic materials in thin, flexible resilient sheets or suitably molded in the U-shape form described could serve as well.
The function of the lining cemented to the inside surface of the stiffener is to protect the optical surfaces of the spectacles from abrasion. A thin, soft flexible sheet material with the texture and frictional qualities of felt or velvet is desirable for this use. The lining is preferably applied to the inner face of the stiffener by means of glue or cement and is carried over the exposed edges to provide additional protection.
The stiffener is readily inserted into conventional slip-in spectacle cases and does not in any way alter their function, utility, or convenience. It will be apparent that the stiffener may be inserted at the time the glass case is manufactured and dispensed in combination with the case, or it may be dispensed separately for use with an existing case or to be transferred from case to case.
The advantage of this feature is in the flexibility and economy it affords the user. Most wearers of spectacles own several pairs and therefore have more than one spectacle case. A single stiffener may be used in all of these whenever its added protection is desired. Furthermore, if a spectacle case wears out, the stiffener may be removed and inserted in the replacement case.
Other details of construction and objects of the invention will become apparent from the following detailed description of the prefered embodiment illustrated in the accompanying drawing in which: